EP1116242B1 - Method and device for filling drums containing dangerous waste - Google Patents

Description

Technical area

The invention relates to a method for ensure the filling of barrels containing waste dangerous, such as radioactive waste from very low activity, previously packaged and compacted to form "pancakes" stacked together on the others inside the barrel.

The invention also relates to an installation for the implementation of this method.

State of the art

In nuclear installations, waste Low activity technologies are first and foremost packaged in metal containers cylindrical. The volume of these containers is, by example, of 120 liters.

The containers containing the waste are then compacted using a press, to obtain "cakes" strongly reduced in volume, in the sense of the height of the containers.

In a later stage, these patties are stacked in cylindrical metal drums. As a general rule, five pancakes are, for example, stacked in each of the barrels.

During a subsequent operation called "blocking" the casks are placed on a vibrating table and filled a blocking material such as mortar or grout of cement.

When a drum is filled with blocking material, it is then closed by means of a lid crimped.

Finally, when the blocking material is dry, the drums are transported to a storage site in long lasting surface.

The invention relates more specifically to the operation blocking, during which the casks containing the patties are filled with a material of blocking.

During this operation, which is carried out workshop, the contaminated air contained in the barrel escapes in the workshop and tends in particular to contaminate the wall outside of the drum and the immediate environment. Indeed, a volume of contaminated air equivalent to that blocking material injected into the barrel escapes outside of it.

There is no solution in the prior art known technique to this problem.

Presentation of the invention

The subject of the invention is precisely a method filling a drum containing waste dangerous, avoiding any dispersion of contamination in the atmosphere of the room, and especially on the outer wall of the drum, due to the air contaminated ejected from the barrel during the blocking operation.

• montage d'un couvercle intermédiaire sur un fût, ledit couvercle comportant une ouverture obturée de façon étanche par un opercule ;
• perforation de l'opercule par une couronne dentée portée par une cloche_de confinement surplombant une extrémité du fût fermée par le couvercle intermédiaire ;
• injection d'un matériau de blocage dans le fût, par un tube d'injection situé à l'intérieur de la couronne dentée ;
• mise en dépression du fût et de la cloche de confinement, dès l'accostage du fût et pendant la perforation et l'injection.

According to the invention, this result is obtained by means of a method of filling drums containing hazardous waste, characterized in that it comprises the following steps:

• mounting an intermediate lid on a barrel, said lid having an opening sealed with a lid;
• perforation of the lid by a ring gear carried by a bell_de confinement overhanging one end of the barrel closed by the intermediate cover;
• injecting a blocking material into the barrel by an injection tube located inside the ring gear;
• depression of the barrel and the containment bell, from the docking of the drum and during perforation and injection.

In the process thus defined, the lid intermediate equipped with its lid ensures confinement tightness of the drum before the perforation of the lid. After perforation, dynamic containment is ensured by the depression of the barrel and the bell confinement. Thus, the contaminated air contained in the drum is sucked as the drum is filled by the blocking material, without this being air is dispersed in the atmosphere of the workshop. We thus avoids any contamination of the wall outside the drum.

According to a preferred embodiment of the invention, the end of filling of the drum is detected by the blocking material, so as to stop the injection of this material.

The detection of the end of the filling of the drum may in particular be provided by at least one cane of bubbling opening inside the ring gear.

In this case, so that the fill level can be precisely controlled, we position advantageously the end of the bubbling cane at a predetermined level below the operculum, after the perforation of it. For this purpose, we can use a laser detector mounted on the bell of confinement and able to measure the distance between this one and the intermediate lid.

Preferably, the operculum is equipped with ballast which, by gravity, ensures the evacuation the barrel of the disc cut in the lid by the crown toothed, so as to avoid total filling or partial of the orifice of the injection tube by effect suction of the operculum.

The perforation of the lid may in particular be performed by moving the barrel upwards by compared to a fixed containment bell. We use advantageously for this purpose lifting means such than a cylinder. Preferably, these elevating means are associated with means able to vibrate the barrel that they support, when filling, in order to improve the penetration of the blocking material into the barrel, among the radioactive waste.

In a variant, the perforation of the lid may also be obtained by moving down the toothed crown or bell.

In particular, to prevent the material from being blockage before injection into the drum, advantageously circulate this material continuously in a closed circuit during the period preceding that injection.

Moreover, after the injection of the material of blockage in the barrel, a cleaning is preferably carried out injection means, that is to say the circuit closed and the nozzle through which the material is injected into the drum.

Finally, after injection of the blocking material in the drum, it is separated from the containment bell and put an outer cover on the drum, above the intermediate cover. The barrel passes then in a crimping machine that crimped the outer cover. The drum is then in a state allowing its storage, before shipment to a place arranged for its very long storage.

• un couvercle intermédiaire apte à être monté sur un fût, ledit couvercle comportant une ouverture obturée de façon étanche par un opercule ;
• une cloche de confinement apte à surplomber une extrémité du fût fermée par le couvercle intermédiaire, ladite cloche portant une couronne dentée apte à perforer l'opercule ;
• des moyens d'injection d'un matériau de blocage, débouchant à l'intérieur de la couronne dentée ; et
• des moyens de mise en dépression du fût et de la cloche de confinement.

The invention also relates to a drum filling installation containing hazardous waste, characterized in that it comprises:

• an intermediate lid adapted to be mounted on a drum, said lid having an opening sealed with a lid;
• a containment bell adapted to overhang one end of the barrel closed by the intermediate lid, said bell carrying a ring gear adapted to perforate the lid;
• means for injecting a blocking material, opening inside the ring gear; and
• means for depression of the drum and the containment bell.

Brief description of the drawings

• la figure 1 est une vue en coupe verticale illustrant le remplissage d'un fût contenant des déchets radioactifs au moyen d'une installation de remplissage conforme à l'invention ;
• la figure 2 est une vue en perspective et en coupe, représentant plus en détail le couvercle intermédiaire placé sur le fût, ainsi que son opercule ; et
• la figure 3 illustre schématiquement les moyens d'injection du matériau de blocage utilisés dans l'installation de remplissage selon l'invention.

A preferred embodiment of the invention will now be described, by way of nonlimiting example, with reference to the accompanying drawings, in which:

• Figure 1 is a vertical sectional view illustrating the filling of a drum containing radioactive waste by means of a filling installation according to the invention;
• Figure 2 is a perspective view in section, showing in more detail the intermediate lid placed on the barrel, and its lid; and
• 3 schematically illustrates the injection means of the blocking material used in the filling installation according to the invention.

Detailed description of a preferred embodiment of the invention

In FIG. 1, reference numeral 10 designates a barrel cylindrical metal in which were placed at nuclear waste of very low activity. More specifically, this nuclear waste is present in the form of slabs 12, stacked on each other inside the shaft 10. Each patties 12 is constituted by a metal package cylindrical filled with nuclear waste very low activity, then compacted inside a hurry.

As already indicated, the invention relates to a method and an installation for realizing a blocking operation, during which a material blocking 14 such as a cement mortar is injected successively into each barrel 10, for immobilize the patties 12 by filling also completely as possible the space left free to inside the barrel 10. In accordance with the invention, the process and installation are designed so that the blocking operation is done by avoiding any dispersion of contaminated air initially contained in the shaft 10 in the atmosphere of the workshop conditioning and in particular on the outer wall of the barrel.

The installation according to the invention comprises a intermediate cover 16, which is mounted on the end upper open drum 10 as soon as the patties 12 were placed in this one. Lid intermediate 16 is then crimped.

As best shown in Figure 2, the lid intermediate 16 is sealed to the part of the barrel 10. For this purpose, it may in particular be fitted in an annular seal 18 which covers the bead 10a forming the upper end barrel 10, then crimped.

The intermediate lid 16, made of sheet metal metal, has in its center a circular opening 20. The diameter of this opening is, for example, of 164 mm in the case of a drum 10 of 570 mm diameter.

The central circular opening 20 of the lid intermediate 16 is initially sealed sealed by a metal cap 22, for example in aluminum, glued on the upper or outer side of the intermediate lid 16. The metal seal 22 constitutes a temporary filling pellet of the drum. It is provided at its center, on its underside towards the inside of the drum 10, a ballast domino 24 constituting weighting means whose function will appear later. As an example, by no means limiting, the mass of the ballast domino 24 can be about 50 g.

On its underside facing inwards of the barrel 10, the intermediate lid 16 comprises at less an anti-flotation member such as three legs 26 welded on the cover 16 and arranged at 120 ° each other on a circle centered on the axis of the lid 16. As an example, by no means limiting, the circle on which are arranged the legs 26 may have a diameter of 350 mm. the legs 26 protrude downwardly inside the barrel 10, on a specific height, for example 45 mm. They thus maintain a minimum free space of the same height between the intermediate lid 16 and the above the stack of slabs 12 placed in the 10. This space helps promote flow subsequent blocking material 14 when the latter is injected into the drum.

The installation according to the invention comprises in addition a dynamic containment bell 28 (FIG. 1) under which is placed the upper part of the barrel 10 closed by the intermediate cover 16, when the blocking operation is performed. In the mode of shown embodiment, the dynamic containment bell 28 is fixed. More precisely, it is fixed under a horizontal partition 30 which equips the workshop of conditioning.

The installation of the upper part of the barrel 10 under the dynamic containment bell 28 is obtained placing the drum 10 on the upper plate of a cylinder 32 constituting lifting means. When the lifting of the drum 10 is completed, its upper end is received inside the containment bell dynamic 28, as illustrated in Figure 1.

In order to improve the filling of the barrel 10 by the blocking material 14 during the blocking operation, means 34 (FIG. 3) able to vibrate the 10 are associated with the cylinder 32. In other words, the latter is a vibrating cylinder.

Diagrammatically, in lines in Figure 1, an anti-fall system consisting of of fingers 35 connected by arms 37 to the partition horizontal 30. When the barrel 10 is in position high, the fingers 35 are placed under the tray cylinder and ensure its maintenance in this position, even in case of cylinder failure 32.

As schematically illustrated on the 3, the barrels 10 are conveyed one after the other above the jack 32 by a conveyor 36, in order to to undergo the blocking operation. They are then evacuated from this station by the same conveyor 36.

According to the invention, the containment bell dynamic 28 supports in its center the ferrule 39, terminated at the bottom by a ring gear 38 (figure 1). This ring gear 38 is placed in the axis of the opening 20 formed in the center of the lid intermediate 16 and its diameter is slightly lower to that of this opening. The ring gear 38 is provided on the whole of its periphery with teeth of saw sharp and deep down. These saw teeth ensure the perforation of the seal 22 at the end of the rise of the shaft 10 under the bell of dynamic containment 28, just before the start of the injection locking material 14.

Holes 37 are drilled all around the support cylindrical toothed ring 38, at a level such that they are under the lid intermediate 16, at the end of the drilling operation of 22. These holes 37 avoid the setting depression of the seal 22 after the piercing and allow good air circulation.

When perforation is performed, the domino ballast 24 which is placed in the center of the lid 22 drives down, by gravity, the disc cut in the cover by the toothed crown 38. The domino of ballast 24 ensures the drop of the disc in the drum and thus prevents this disc from staying inside the toothed ring 38 and to close the pipes which come out inside the crown. He avoids also to the disk to float on the surface on the material blocking 14.

The installation according to the invention comprises in addition means 40, for injecting the material of blocking 14 in the barrel 10. These injection means 40, which will be described in more detail later in Referring to FIG. 3, in particular include a nozzle injection 42 which opens inside the crown toothed 38, as shown in Figure 1. The nozzle injection nozzle 42 is oriented downwards and disposed of preferably along the axis of the ring gear. When the cover 22 has been perforated by the ring gear 38, the implementation of the injection means 40 can inject the blocking material 14 directly inside barrel 10 without breaking the confinement of this latest.

The installation according to the invention comprises furthermore means 44 for depressing the drum 10 and from inside the dynamic containment bell 28. These means of depression 44 include in particular one or more air suction lines 46, which open into the ferrule 39 bearing the ring gear 38. The pipe or conduits air suction 46 are connected to suction means 47 able to extract the contaminated air driven from the barrel 10, as and when the material is injected blocking 14, while maintaining a depression in the drum and inside the containment bell dynamic 28, compared to the external environment. As a non-limiting illustration, depression generated by the depression means 44 is, for example, about 2660 Pa.

The means of depression 44 include in addition very high efficiency filters 49 capable to retain all the contaminating dust contained in the sucked air.

The suction means 47 are advantageously doubled, in order to avoid any loss of confinement deterioration of the main vacuum system or a loss of power supply.

Advantageously and as schematically illustrated in Figure 1, a deflector 48 is placed inside the ring gear 38, immediately under the injection head 42, to direct the material 14 to the periphery of the barrel 10. On eliminates any risk of clogging, even if temporary, ducts 46 for suction of air. Indeed, in the absence of deflector, a slope of blocking material could form on the top of the stack of patties 12.

Outside the ferrule 39 carrying the crown toothed 38, the upper wall of the bell dynamic confinement 28 supports a laser detector 50 turned towards the intermediate lid 16. The detector laser 50 can measure the distance that separates the containment bell 28 of the intermediate lid 16. In connection with a control circuit (not shown) of the lift cylinder 32, the laser detector 50 forms and means for positioning the low end at least one bubbling cane 52 at a predetermined level below the lid 22, after the perforation of it (two bubble rods 52 are used, preferably, as shown in Figure 1). In other words, when the distance measured by the laser detector 50 reaches a predetermined value, the raising of the barrel 10 ensured by the lift cylinder 32 is stopped. The low ends of the bubbling canes 52 are then at a predetermined level below of the intermediate cover 16. The control of this positioning allows precise piloting of the level filling the barrel 10 with the blocking material 14, using the bubbling rods 52.

For this purpose, the lower parts of the canes of bubbling 52 (Figure 1) are placed inside the ferrule 39 bearing the ring gear 38. The level of low ends of the bubbling rods 52 is such that, when the barrel 10's rise was stopped in response to the measurement made by the laser detector 50, these ends are at a slightly lower level to that of the intermediate lid 16. for example, the low ends of the bubbling canes 52 may be 4 mm below the level of the intermediate lid 16. Bubbling sticks 52 thus constitute means for detecting the filling 10. In other words, when canes bubbling 52 are blocked by the blocking material 14 at the end of the filling, it is certain that the cask is completely filled. The filling of the drum is therefore stopped.

When two bubbling rods 52 are used as shown in Figure 1, they are placed advantageously in diametrically opposed positions relative to the vertical axis of the bell of 28. They shall then ensure the redundancy of detection.

In Figure 3, there is shown schematically level detection means 54 to which are connected with the bubbling rods 52. These means 54 of level detection control automatic closing two level detection valves 56a and 56b, placed in a feed circuit of the nozzle 42 in blocking material 14. This supply circuit constitutes, with the injection nozzle 42, the means 40. A third valve 56c, located immediately upstream of the injection nozzle 42 serves relief valve and allows the control of the flushing of the supply circuit. She is ordered from the room of driving, by an all or nothing command.

As shown in Figure 3, the fuel system of the nozzle 42 comprises a closed circuit 58 connected to the injection nozzle 42 by a pipe 60 in which are placed the valves 56b and 56c.

The closed circuit 58 comprises a hopper 62 of filling and storage of blocking material 14. The capacity of the hopper 62 is designed to allow the filling of at least one drum 10. The hopper 62 is filled with the desired volume of blocking material, since a kneader (not shown), admitted by a pipe 64 through a valve 66. The closed circuit 58 allows to circulate continuously and in a loop the material blocking 14, to prevent its caking, increase its life time and limit the effects of fouling pipes, before this material is injected in the drum 10. It is equipped for this purpose with means of such as a peristaltic pump 68. The valve 56a controlled by the level detection system 54 is placed in the closed circuit 58, immediately downstream of the bypass by which the circuit 58 is connected to the injection nozzle 42 through the driving 60.

A pipe 74, provided with a valve 76, connects the water distribution network to the pipe 60 between two valves 56b and 56c placed thereon. This pipe 74 allows, by injection of water under pressure, to flush the central and low parts of the injection nozzle 42 when the barrel that has just been filled was evacuated. It is put into action before the next barrel does not arrive below the bell of dynamic containment 28. Effluent recovery rinsing is carried out by a retractable tray (no represented) who comes to live under the bell of containment 28, instead of the barrel. Effluents are then directed to a specialized facility of treated water treatment.

Other valves 82 are provided in different locations in the closed circuit 58. In addition, a pipe 84 provided with a valve 86 opens into the circuit 58, close to the suction of the means of 68. This pipeline ensures the cleaning of the entire circuit, including the introduction of a foam ball, by the pipe 84, which ensures the evacuation of the residual blockage to a drain pipe 87, equipped with a stop valve 88. The final rinse of the closed circuit is done by injecting clear water into the hopper 62 (pumping means 68 in operation) and recovery of effluents in the retractable tray then accosted under the bell 28.

Only part of the closed circuit 58 is inside the packaging workshop in which is carried out filling the barrels 10. A portion of the containment partition 88 delimiting this workshop was shown schematically in the figure 3. That part of circuit 58 located outside of the packaging workshop includes the hopper 62 and the pumping means 68.

The entire installation is advantageously driven by automated control-command means (not shown)

When a barrel 10 is conveyed to the station filling in which the blocking operation is realized in accordance with the invention, it contains the slabs 12 and its upper end is closed off sealed way by the crimped intermediate cover 16 whose central opening 20 is closed by the operculum 22. As soon as the drum 10 is brought over the lift cylinder 32 by the conveyor 36, its displacement horizontal is stopped and the drum is raised to the position shown in Figure 1. In this position, controlled by the laser detectors 50, the cover 22 is perforated by the ring gear 38. The disc cut into the operculum immediately falls on the stack of slabs 12, by gravity, because of the ballast domino mass 24.

Despite this perforation, the confinement of the barrel 10 remain assured until the end of the filling by the dynamic containment bell 28 put into depression by means 44 of depression.

The injection of the filling material 14 into the drum then starts under the action of the pumping means 68, after opening valves 56a and 56c placed in the pipe 60. Simultaneously, the barrel 10 is put in vibration by the vibrating means 34, associated with the cylinder 32.

The injection of the filling material 14 is continues until the bubbling canes 52 detect the arrival of the free level of the blocking material to immediate proximity of the intermediate lid 16. The level detection means 54 then automatically close the valves 56a and 56b and the injection is stopped.

Then, the jack 32 is again actuated to lower the barrel 10 on the conveyor 36 and route it to the next station where a cover outside (not shown) is put in place. More precisely, the outer cover is mounted on the barrel above the intermediate cover 16 and crimped on the bead 10a of the drum.

The process and the installation that comes to be described allow to carry out the operation of blocking by ensuring a perfect mastery of confinement. Any dispersion of contamination in the atmosphere of the workshop, including any contamination of the outer wall of the barrel is thus avoided.

Claims (24)

1. Process for filling drums (10) containing dangerous wastes (12), characterised in that it comprises the following stages:

   assembly of an intermediary lid (16) on a drum (10), said lid comprising an opening (20) closed in a sealed fashion by a cap (22);

   perforation of the cap by a toothed crown (38) carried by a containment hood (28) overhanging one end of the drum (10) closed by the intermediary lid (16);

   injection of a blocking material (14) into the drum (10), by means of an injection tube (42) located inside the toothed crown (38);

   negative pressure application to the drum (10) and the containment hood (28), as soon as the drum is set in place and during perforation and injection.
2. Process according to Claim 1, in which the end of filling the drum (10) by the blocking material (14) is detected and the injection is stopped.
3. Process according to Claim 2, in which the end of filling the drum is detected by at least one bubble tube (52) opening inside the toothed crown (38). the end
4. Process according to Claim 3, in which the end of the bubble tube (52) is positioned at a predetermined level below the cap (22), after perforation of the latter.
5. Process according to any one of the preceding Claims, in which the cap (22) is equipped with ballast means (24) ensuring evacuation into the drum (10), by gravity, of a disc cut out in the cap at the time of its perforation.
6. Process according to any one of the preceding Claims, in which the cap (22) is perforated by displacing the drum (10) upwards, in relation to a fixed containment hood (28).
7. Process according to any one of the preceding Claims, in which the drum (10) is made to vibrate during injection of the blocking material (14).
8. Process according to any one of the preceding Claims, in which, before injection of the blocking material (14), the latter is made to circulate continuously in a closed circuit (58).
9. Process according to any one of the preceding Claims, in which, after injection of the blocking material (14) into the drum (10), cleaning of the means of injection (40) is carried out.
10. Process according to any one of the preceding Claims, in which, after injection of the blocking material (14) into the drum (10), the latter is separated from the containment hood (28) and an external lid is placed on the drum (10), on top of the intermediary lid (16).
11. Installation for filling drums (10) containing dangerous wastes (12) , characterised in that it comprises:

    an intermediary lid (16) able to be mounted on a drum (10), said lid comprising an opening (20) closed in a sealed fashion by a cap (22);

    a containment hood (28) able to overhang an end of the drum (10) closed by the intermediary lid, said hood having a toothed crown (38) able to perforate the cap (22);

    means of injection (40) of a blocking material (14), opening inside the toothed crown (38); and

    means (44) of negative pressure application for the drum (10) and the containment hood (28).
12. Installation according to Claim 11, comprising in addition means (52, 54) for detecting the end of filling the drum (10) with the blocking material (14).
13. Installation according to Claim 12, in which the means for detecting the end of filling the drum (10) comprise at least one bubble tube (52) opening inside the toothed crown (38).
14. Installation according to Claim 13, comprising in addition means (50) for positioning the end of the bubble tube (52) at a predetermined level below the cap (22).
15. Installation according to Claim 14, in which the means for positioning the end of the bubble tube (52) comprise a laser detector (50) mounted on the containment hood (28) and able to measure the distance between the latter and the intermediary lid (16).
16. Installation according to any one of Claims 11 to 15, in which the lid (22) is provided with ballast means (24) in a part able to be perforated by the toothed crown (38).
17. Installation according to any one of Claims 11 to 16, in which the intermediary lid (16) comprises, on a face able to be turned towards the interior of the drum (10), at least one anti-float organ (26) able to rest on the radioactive wastes (12), around the opening (20), to provide a free space between these wastes and the intermediary lid (16).
18. Installation according to any one of Claims 11 to 17, comprising in addition lifting means (32), able to lift the drum (10), the containment hood (28) being mounted in a fixed setting above said lifting means.
19. Installation according to Claim 18, in which the means (34) able to make the drum (10) vibrate are associated with the lifting means (32).
20. Installation according to any one of Claims 11 to 19, in which the means of injection (40) of the blocking material comprise a closed circuit (58) linked to the injection head (42) of said material, opening inside the toothed crown (38).
21. Installation according to Claim 20, in which a deflector (48) is placed beneath the injection head (42), so as to direct the blocking material (14) towards a peripheral region of the drum (10).
22. Installation according to one or the other of Claims 20 and 21, in which the closed circuit (58) comprises:

    a hopper (62) for filling and storing the blocking material; and

    pumping means (68) able to make the blocking material circulate from the hopper (62) to the injection head (42) and continuously in the closed circuit.
23. Installation according to Claim 22, in which the closed circuit (58) comprises in addition means (84, 74) for cleaning said circuit and the injection head (42).
24. Installation according to any one of the Claims 11 to 23, in which the means (44) for negative pressure application for the drum (10) comprise at least one pipe (46) linking the containment hood (28) to suction means (47) through filter means (49).

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